Known in the present of the art is a method for machining materials (U.S. Pat. No. 1,483,205), wherein compressed air is supplied through a vortex tube to an air stream ionizing means, a corona discharge being applied for the purpose. Once electric current has been applied to the corona-discharge electrode, a corona discharge occurs and the electric field of said discharge ionizes and ozonizes the surrounding air, whereupon the ionized and ozonized air stream is fed, through an inlet nozzle, to the machining zone so as to cool the cutting tool and the material being machined. In addition, the ionized air stream promotes formation of a fine oxide film on the surface of the material being machined and of the cutting tool. Such an oxide film serves as lubricant in the machining process which reduces friction and hence decreases heat evolution in the machining zone.
However, the method discussed before fails to provide adequately efficacious cooling and lubrication of the surface of the material being machined and of cutting tool. Considerable convective and gas-dynamic streams which prevent the ionized and ozonized air stream from getting to the machining zone. Thus, formation of an oxide film on the surface being machined and on that of the cutting tool is less reliable, which results in low cutting tool endurance and affected quality of surface finish.
The method described above can be carried into effect through the use of a device for machining materials (U.S. Pat. No. 1,483,205), comprising a negative-polarity current source, a unit for establishing an air stream, and an air stream ionizing means having a corona-discharge electrode electrode connected to the current source. The air ionizing means appears as a stub pipe accommodating the corona-discharge electrode arranged lengthwise the stub pipe. The air stream establishing unit comprises a compressed air source which communicates, via a vortex tube, with the entrance to the air-stream ionizing means.
The device discussed above suffers from the same disadvantages as the method described before.